Field Of The Invention
This invention relates to video monitors, and more particularly, to systems for simultaneously monitoring a plurality of video signals.
Prior Art
Simultaneous observation of a number of concurrent video signals from a number of video channels is not easily accomplished. These video signals are provided by a number of sources such as broadcast channels, narrowcast channels, cablecast channels, groups of directly routed video-modulated signals, or groups of directly routed video signals.
A single monitor is used to sequentially display video information from some or all of the source channels or signals by sequential selection.
For simultaneous viewing of video information from a plurality number of source channel or signals, a number of CRT monitors are arranged as an array of video monitors to simultaneously display in real time the video information. This approach consumes a great deal of power and space.
Another technique converts the video signals to a digitized format and stores the digitized video information from each video channel in a video frame buffer, which is a large-capacity, high speed memory device. Digitized video information is read into this memory device and subsequently read out at the pixel rate of a viewing device to display the video information on, for example, one of a plurality of smaller viewing panels on a raster-scanned CRT display device. This technique requires a great amount of high-speed memory storage capacity to store digitized information for all of the channels to be displayed because information from each signal must be captured and stored in the frame buffer.
It is desirable to simultaneously display and monitor a number of video signals without sequentially selecting each source for display or without dedicating a monitor device to each source.